The ship was buried as junk two centuries ago - landfill to expand a bustling little island of commerce called Manhattan.
When it re-emerged this week, surrounded by skyscrapers, it was an instant treasure that popped up from the mud near ground zero.
A 9.7m piece of the vessel was found in soil 6m under street level, amid noisy bulldozers excavating a parking garage for the future World Trade Centre.
Near the site of so many grim finds - September 11 victims' remains, twisted steel - this discovery was as unexpected as it was thrilling.
Historians say the ship, believed to date to the 1700s, was defunct by the time it was used around 1810 to extend the shores of lower Manhattan.
"A ship is the summit of what you might find under the World Trade Centre - it's exciting!" said Molly McDonald, an archaeologist who first spotted two pieces of hewn, curved timber - part of the frame of the ship - peeking out of the muddy soil at dawn on Tuesday.
By Thursday, she and three colleagues had dug up the hull from the pit where a section of the new trade centre is being built.
A steep, hanging ladder trembled with each step down into chaotic mounds of dirt, dwarfed all around by Manhattan skyscrapers rising into the July sun.
People sank in the mud as they walked and grasped pieces of the historic wood for support - touching the centuries-old ship that may once have sailed the Caribbean, according to marine historian Norman Brower, who examined it Thursday.
"It smells like low tide, this muck," said McDonald as she stood on the weathered planks, sniffing the dank odor that hovered over them in the hot summer morning.
The ship harbours many mysteries still to be solved: "Where was it built? How was it used? Why was it sunk?"
McDonald and archaeologist A. Michael Pappalardo made the discovery on Tuesday at about 6.15am, just as they started their shift observing construction in the pit at the southern edge of ground zero.
The two work for AKRF, a New York environmental consulting firm hired to document artefacts discovered at the trade centre site.
"We noticed two curved timbers that a backhoe had dislocated," McDonald said.
Joined by two more archaeologists, they started digging with shovels, "and we quickly found the rib of a vessel and continued to clear it away and expose the hull over the last two days."
Brower, the historian, works in Mystic, Connecticut - renowned for its historic vessels. He told the archaeologists that it was an oceangoing vessel that might have sailed the Caribbean, as evidenced by 18th Century marine organisms that had bored tiny tunnels in the timber.
The vessel's age will be estimated after the two pieces that first popped up are tested in a laboratory through dendrochronology - the science of using tree rings to determine dates and chronological order. Also unknown is what kind of wood was used to build the ship.
A 45kg iron anchor was found a few yards from the hull, possibly from the old vessel.
There were also traces of human life nearby - "pieces of shoes all over," said McDonald, who had no idea how they got there.
The ship likely got there because of the effort to extend lower Manhattan into the Hudson River in the 1700s and 1800s using landfill.
Cribbing usually consisted of logs joined together - much like a log cabin - but a derelict ship was occasionally used.
The ship discovered Tuesday was weighted down and sunk to the bottom of the river, as support for new city piers in a part of Manhattan tied to global commerce and trade.
A similar find emerged a walk away in 1982, when archaeologists found an 18th Century cargo ship on Water Street.
The remains of the latest discovery will be removed in the coming days, but the timber is so delicate it's unclear how much of it will remain intact.
The surrounding water acted as a preservant for the wood for centuries, McDonald said, but the remains began to deteriorate immediately upon contact with oxygen.
"We're mostly clearing it by hand because it's kind of fragile," McDonald said, meaning shovels are used. Construction equipment could come in handy later in the process.
On Thursday, archaeologists were quickly sketching, measuring and photographing the ship remnants to help them analyse the find later - the two pieces of timber that signaled the discovery were taken away immediately. It was not clear from the 9.7m piece how long the whole ship might have been.
Another fascinating detail might emerge as work progresses - coins traditionally placed under a vessel's keel block as a symbol of good fortune and safe travels.
But the team is already feeling pretty lucky. "I kept thinking of how closely it came to being destroyed," Pappalardo said.
Somehow, the workers operating the bulldozers missed the bulk of the ship, catching only the two timbers as they excavated ramps that will connect to an underground parking garage at the rebuilt trade centre.
Within the fenced-off, 16-acre site in downtown Manhattan, steel for a planned 541m skyscraper has risen 24 storeys.
The memorial to victims of the September 11 attacks, a multibillion-dollar transit hub and a second office tower are under construction. More office towers and a performing arts centre are also part of the original plan.